The Twentieth Century Society

Campaigning for outstanding buildings


You can help save our irreplaceable C20th buildings and design.

Join our society

Your passion for outstanding 20th century buildings and design gives us the power to promote and save them.

Everything we achieve, we achieve thanks to our members. They give us a forceful voice. They’re our eyes and ears, always alert to buildings and design under threat. And they ‘walk the talk’ – joining us to back campaigning action and often volunteering their time and expertise to help run the C20 Society.

Why not become a C20 society member too? Benefits include advance booking for our events, member discounts and a free copy of our regular magazine, C20.

Buildings at risk

Read our latest list of the top ten most threatened buildings and designs of our period.

  • See all buildings


Help us save the irreplaceable C20th buildings and design that still shape Britain today. Your donation will help run campaigns, identify new threats, enlist experts and raise our profile. Donations also support events and publications that build interest in post-1914 architecture across all generations and help stop demolition.


Sign the petition

We are currently campaigning to save Richmond House in Whitehall, London. If you agree that demolishing this Grade II* listed building by William Whitfield for a temporary House of Commons chamber would be a shameful waste of public money and our C20th heritage, then please sign our petition.

Save a building

Do you believe that your house or office should be listed? Are you concerned that an outstanding building in your area may be under threat? Use our practical guidelines to find out exactly what you can do to save a C20th building.

Volunteer your talent

Use your spare time and talents to help us as a valued C20 Society volunteer.

  • Read more

Act local

We campaign across Britain and our regional network is growing, with seven local groups currently active. Our local groups give us eyes, ears and a powerful voice, wherever irreplaceable buildings and design are under threat. Find out what C20 Society is doing in your region.